"Not at all. The whole sequence becomes clear when we strive to complete our equational balance in the first phase. The bartender poured an unconsumed drink back into the bottle after whoever ordered it walked out without drinking it." Of course! The logic of it hit Donovan and me at the same moment. Donovan said, "How in the hell did you ever think of that?" He meant it as a compliment but Dalrymple did not take it as such. "I didn't think of it, you fool. I worked it out. Haven't you understood anything I've told you? It's all here in the progression of the equation. Incidentally, that factor is the pivot of the whole sequence. Your stupid logic should carry you on from there." "Somebody was trying to poison somebody else!" Donovan said. "There had to be two men," I added. "They came in and ordered drinks. One poured poison in the other's drink. Then they left without--" Dalrymple was leering at me. "How about one man and--suicide?" I swore at myself inwardly for giving him the opening. But he turned back to his symbols and said, "By sheer blundering chance you hit it, though. It was two men and attempted murder." Donovan wasn't having much to say. Dalrymple threw down the pencil. "I'll be going now. I have more important things to do." "Can you give us the names of the two men?" I asked, and again swore at myself for being over-eager. Dalrymple gave me a long, disgusted clinical look. "I can, but I won't. It would take another hour to round out the equation and I don't feel like doing all your work for you. If you can't take what I've given you and tie up the case, then you'd better both resign." He got up and started to leave. At the door, he turned. "I live at the Crestwood Hotel if you want to get in touch with me again." He sneered. "Maybe you'll need help some day in tying your shoes." He left. Neither Donovan nor I made any attempt to stop him. After a long minute Donovan said, "We can't let him go. He's involved in that killing. He's got to be. How else would he know?" "Are you sure he's involved?" Donovan didn't answer. He picked up the pencil and snapped it in two with a savage gesture. "The sneering little son-of-a--" "Besides, we've got no proof he was right in anything he said." "Let's go find out." We found out. It didn't take long and we got a citation. We hit Garver with one question--"Who was in the bar just before Davis entered?" and he collapsed right in our laps. We got all he knew and it wasn't hard to trace down two guys named Kinder and Walpole.